1. Field of the Invention
The present invention relates to the immobilization of metal-contaminated particulate matter, particularly to catalyst used in the removal of metals from contaminated hydrocarbons.
2. Description of the Prior Art
A good deal of work by Gladrow and associates relates to the field of hydrocarbon conversion and particularly to metal-contaminated catalyst: U.S. Pat. Nos. 4,287,048, 4,289,606, 4,308,129, 4,292,169, 4,147,613, 4,097,410 and 4,376,039 also several patents to TU and associates have been issued for developing techniques for dealing with accumulations of metals: U.S. Pat. Nos. 4,299,688, 4,263,174 and 4,312,744. Most of the above patents are classified in US class 208, subclass 120 and class 502 subclass 455Z.
Sorbent materials for removing metals from catalyst have been taught by Yan; U.S. Pat. No. 4,334,976 and by Bartholic U.S. Pat. Nos. 4,243,514, 4,309,274, and 4,328,891. These are generally classified in U.S. Patent class 208 subclass 91.
Various patents have taught a variety of catalytic cracking catalysts for the use with hydrocarbons including U.S. Pat. No. 4,208,269 to Gladrow and U.S. Pat. No. 4,137,152 to Chester and many others.
Most of the prior art which have been issued prior to 1975 has been concerned with the cracking of virgin gas oils e.g. in a fluid catalytic cracking (FCC) apparatus. In such operations nickel has been considered the principally deleterious metal contaminant and the term "nickel equivalence" has been calculated as: EQU Ni equivalents=4Ni+V+Fe or EQU Ni equivalent=Ni.times.V/4.times.Fe/5
As the use of more contaminated distress feedstocks e.g. reduced crude oils became necessary due to the increasing cost of petroleum feedstocks, the present inventors and others recognized vanadium as being probably the most deleterious of all metal contaminants, particularly its effect on zeolite structures contained in cracking catalyst and also its affect on agglomeration and plugging of sorbents used for demetalizing feedstocks.
Therefore, the present invention is concerned with the non-ionic deposition of lanthanum and/or lanthanum rich rare earths onto the particulate matter e.g. catalyst, which is contaminated with (or will be contaminated with) vanadium and/or other heavy metal contaminants. The non-ionic deposition of lanthanum rich material may occur prior to, during or after vanadium contamination and is preferably accomplished by physical means, such as by precipitating the lanthanum rich rare earths onto formed particulate matter.